Monoenergetic positron beam, positron lifetime, and Hall-effect measurements in III–V epilayers grown at low temperatures by molecular beam epitaxy

Author(s):  
N. Hozhabri
1993 ◽  
Vol 300 ◽  
Author(s):  
Tsutomu Iida ◽  
Yunosuke Makita ◽  
Shinji Kimura ◽  
Stefan Winter ◽  
Akimasa Yamada ◽  
...  

ABSTRACTLow energy (100 eV) impinging of carbon (C+) ions was made during molecular beam epitaxy (MBE) of GaAs using combined ion beam and molecular beam epitaxy (CIBMBE) technologies for the growth temperature ( Tg ) between 500 °C and 590 °C. 2 K photoluminescence (PL), Raman scattering and Hall effect measurements were made for the samples. In the PL spectra two specific emissions, “g” and [g-g], were observed which are closely associated with acceptor impurities. PL and Hall effect measurements indicate that C atoms were very efficiently introduced during MBE growth by CIBMBE and were both optically and electrically well activated as acceptors even at Tg=500 °C. The results reveal that defect-free impurity doping without subsequent annealing can be achieved by CIBMBE method.


1985 ◽  
Vol 46 ◽  
Author(s):  
L.T. Parechanian ◽  
E.R. Weber ◽  
T.L. Hierl

AbstractThe simultaneous molecular beam epitaxy (MBE) growth of (100) and (110) GaAs/GaAsintentionally doped with Si(∼lE16/cm^3) was studied as a function of substrate temperature, arsenic overpressure, and epitaxial growth rate. The films wereanalyzed by scanning electron and optical microscopy, liquid helium photoluminescence (PL), and electronic characterization.For the (110) epitaxal layers, an increase in morphological defect density and degradation of PL signal was observed with a lowering of the substrate temperature from 570C. Capacitance-voltage (CV) and Hall Effect measurements yield room temperature donor concentrations for the (100) films of n∼l5/cm^3 while the (110) layers exhibit electron concentrations of n∼2El7/cm^3. Hall measurements at 77K on the (100) films show the expected mobility enhancement of Si donors, whereas the (110) epi layers become insulating or greatly compensated. This behavior suggests that room temperature conduction in the (110) films is due to a deeper donor partially compensated by an acceptor level whose concentration is of the same order of magnitude as that of any electrically active Si. Temperature dependent Hall effect indicates that the activation energy of the deeper donor level lies ∼290 meV from the conduction band. PL and Hall effect indicate that the better quality (110) material is grown by increasingthe arsenic flux during MBE growth. The nature of the defects involved with the growth process will be discussed.


2016 ◽  
Vol 119 (24) ◽  
pp. 245702 ◽  
Author(s):  
Akira Uedono ◽  
Marco Malinverni ◽  
Denis Martin ◽  
Hironori Okumura ◽  
Shoji Ishibashi ◽  
...  

1996 ◽  
Vol 69 (3) ◽  
pp. 397-399 ◽  
Author(s):  
Albert Chin ◽  
W. J. Chen ◽  
F. Ganikhanov ◽  
G.‐R. Lin ◽  
Jia‐Min Shieh ◽  
...  

1994 ◽  
Vol 49 (7) ◽  
pp. 4689-4694 ◽  
Author(s):  
P. W. Yu ◽  
G. D. Robinson ◽  
J. R. Sizelove ◽  
C. E. Stutz

1997 ◽  
Vol 40 (2) ◽  
pp. 214-218
Author(s):  
Nuofu Chen ◽  
Hongjia He ◽  
Yutian Wang ◽  
Lanying Lin

1992 ◽  
Vol 281 ◽  
Author(s):  
S. Arscott ◽  
M. Missous ◽  
L. Dobaczewski ◽  
P. C. Harness ◽  
D. K. Maude ◽  
...  

ABSTRACTShubnikov-de Haas and Hall measurements have been performed on singly delta doped GaAs(Si) structures, grown by molecular beam epitaxy, enabling us to study the effects of illumination and temperature upon bulk and individual subband, mobilities and carrier concentrations. In a highly doped sample, where the peak 3D electron concentration approaches 2×1019cm−3, we have observed novel changes in subband transport characteristics, not observed in the lower doped samples, which we attribute to the presence of DX centre phenomena. This paper explains the variations in individual subband transport properties due to a possible shift of the electronic wave functions contained in the potential well. This shift occurs due to a recombination-autoionization(R-A) process involving filled DX centres and free holes upon sample illumination at low temperatures.


1991 ◽  
Vol 231 ◽  
Author(s):  
T. Sands ◽  
J.P. Harbison ◽  
S.J. Allen ◽  
M.L Leadbeater ◽  
T.L Cheeks ◽  
...  

AbstractEpitaxial films of ferromagnetic τMnAl with perpendicular magnetization have been grown on {100}AlAs/GaAs substrates by molecular beam epitaxy. A multistep growth procedure involving the formation of a template followed by codeposition and subsequent annealing yields thin epitaxial τMnA1 films that exhibit the extraordinary Hall effect with nearly ideal hysteretic characteristics.


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